An electron beam drawing apparatus as an exemplary charged particle beam drawing apparatus draws on a mask substrate in which a Cr film as alight shielding film and a resist film are stacked on a surface of a glass substrate as mask, for example, by irradiating with an electron beam. At this time, the mask substrate is charged by irradiating with the electron beam. When the mask substrate is charged, a trajectory of an electron beam is bent due to an electric field formed by the charged mask substrate, and the electron beam is irradiated on a position misaligned from a position to be radiated. Consequently, a drawing accuracy deteriorates. Thus, a mask cover having an earth mechanism with a grounded earth pin is placed on the mask substrate such that the earth pin of the earth mechanism penetrates through the resist film and contacts the Cr film. Drawing is performed on the mask substrate with the grounded Cr film, deterioration in drawing accuracy is suppressed.
However, there is a problem that particles are generated when the earth pin penetrates through the resist film, and the generated particles adhere to the surface of the mask substrate. Adhesion of particles to the mask substrate causes drift of the electron beam and pattern error, which deteriorates a drawing accuracy.